HYBRIDIZATION 



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wooden label with copper wires which is attached to the ear. If it is de- 

 sired to make a second pollination the bag containing pollen maybe tied to 

 the plant alongside the ear and the same process repeated one or two 

 days later. By close observation of the developing stigmas and pollinat- 

 ing at the most propitious time well developed ears can be secured from 

 a single pollination. Fig. 142 illustrates the principal features above 

 described. 



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FIG. 142. Hybridization of maize. Right, plant jugt previous to anthesis with leaves 

 subtending ears stripped off; left, the same plant with bag enclosing tassel and cylinders 

 covering ears. 



Method of Hybridizing Wheat. This plant has numerous hermaph- 

 rodite flowers arranged in a branched spike (Fig. 143, upper left). Each 

 spikelet bears two rows of bracts or glumes (Fig. 143, 2). The lowest 

 two bracts are sterile but each of the next four usually subtends a flower 

 while at the top of the spikelet are two or three rudimentary flowers. 

 Each flower consists of an ovary with two much branched stigmas (Fig. 

 143, 12, 13) and three stamens which are shown in cross-section in Fig. 



